"This year the Commission on Human Rights must act forcefully and decisively to reverse the situation that could turn a human rights crisis into a human rights catastrophe," said Irene Khan, the secretary general of the advocacy group.

Khan said the 53 member states in the rights commission faced a test with a draft resolution condemning violations in the Himalayan kingdom, amid "widespread" torture and an increase in killings by security forces.

King Gyanendra dismissed Nepal's four-party coalition government on February 1, clamping down on political opposition. A Maoist insurgency has also claimed more than 11,000 lives since 1996.

"The Maoists have also committed massive abuse of human rights: they regularly abduct civilians, torture them, force them to join their ranks or kill them," Khan said.

She insisted that failure to take action on Nepal would prove that the UN body was not only powerless to face up to violations in big countries because of "powerful political interests, but that the Commission is incapable of acting to prevent a human rights crisis in any country."

Switzerland has been circulating a draft of resolution which it hopes to formally submit to the commission next month, diplomats said. Khan said it appeared to be "very comprehensive".

Nepal has had the highest number of disappearances in the world for the last two years, according to Amnesty.

Meanwhile, at least 19 Nepali Congress (NC) activists were arrested Wednesday across Nepal for protesting against King Gyanendra's February 1 power grab, the country's main opposition party said.

"Police arrested at least 19 NC activists from four different districts of the country for holding anti-king protests," it said in a statement.

"The NC has been holding peaceful and non-violent protest programmes since March 18 against the king's proclamation," it added.

Authorities could not be reached to confirm the arrests.

Around 50 political and student NC activists were detained around the country on Tuesday, a day after police arrested at least 138 others. Scores more have also been detained in recent weeks.